Positive expiratory pressure device

ABSTRACT

A multi-use, hand held, single patient oscillatory positive expiratory pressure respiratory therapy device which is easily assembled and disassembled for cleaning, and which is not position dependent during therapy, but operable through a wide range of device orientation.

This application is a continuation of copending application Ser. No.10/396,218 filed Mar. 24, 2003 now U.S. Pat. No. 7,059,324, which is acontinuation-in-part of application Ser. No. 09/449,208 filed Nov. 24,1999 now U.S. Pat. No. 6,581,598.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to a hand-held, multi-use, singlepatient positive oscillatory expiratory pressure respiratory therapydevice and, in particular, to an easily assembled and disassembledpositive oscillatory expiratory pressure respiratory therapy devicewhich is not position dependent during therapy, but operable through awide range of device orientation.

2. Description of Related Art

Persons who suffer from mucus-producing respiratory conditions thatresult in large amounts of mucus being produced in the lungs oftenrequire assistance in the removal of these secretions. If-thesesecretions are allowed to remain in the lungs, airway obstruction occursresulting in poor oxygenation and possible pneumonia and/or death. Oneof the clinically recognized treatments for this condition is atechnique known as positive expiratory pressure therapy or PEP. With PEPtherapy, a patient exhales against a resistance to generate expiratorypressure at a substantially constant rate of flow. Prescribed expiratorypressures are generally in the range of 10-20 cm of H₂O, although otherpressure ranges and pressures can be used, with a preferred flow rate ofbetween 10-25 liters per minute.

In the use of PEP therapy, a patient breaths through an orificerestricter to generate a positive pressure in the lungs duringexhalation, with the pressure falling to zero at the end of theexhalation. By selection of the proper-sized orifice, a given pressureis determined for the exhalation flow rate generated by an individualpatient. This extended, substantially constant, flow ofelevated-pressure exhalation has been shown to be effective for movingsecretions trapped in the lungs to the larger airways where thesecretions can then be removed through coughing. It has also been foundthat in the treatment of patients having chronic obstructive pulmonarydisease (COPD), chronic bronchitis, cystic fibrosis, atelectasis, orother conditions producing retained secretions, treatment with PEPtherapy is improved by combining positive expiratory pressure therapywith airway oscillation and intermittent air-flow acceleration. To thisend a hand-held, single patient multi-use, positive expiratory pressurerespiratory therapy device was developed by assignees of the presentinvention, and is the subject matter of a co-pending application, Ser.No. 09/449,208, filed Nov. 24, 1999 for “POSITIVE EXPIRATORY PRESSUREDEVICE”.

The present invention comprises a positive oscillatory expiratorypressure respiratory therapy device which is easily assembled anddisassembled for the purpose of cleaning, and is not position dependentfor operation during PEP therapy. In addition, the translucency of thedevice housing permits inspection of the interior to insure thatcondensate is not being retained in the device, and the deviceconstruction is such that any condensate forming in the device may beeasily removed.

SUMMARY OF THE INVENTION

The present invention is directed to overcoming one or more of theproblems or disadvantages associated with the relevant technology. Aswill be more readily understood and fully appreciated from the followingdetailed descriptions of preferred embodiments, the present invention isembodied in a positive oscillatory expiratory air pressure respiratorytherapy device which is easily assembled and disassembled for cleaningand not position dependent for operation.

DESCRIPTION OF THE DRAWINGS

Further objectives of the invention, together with additional featurescontributing thereto and advantages accruing therefrom, will be apparentfrom the following description of preferred embodiments of the inventionwhich are shown in the accompanying drawings with like referencenumerals indicating corresponding parts throughout, wherein:

FIG. 1 is a perspective view of a first embodiment of the assembledinvention;

FIG. 2 is an exploded perspective view of the invention illustrated inFIG. 1 with portions removed to better illustrate the internal structurethereof;

FIGS. 3, 4, 5 and 6 are, respectively, an upper and lower perspectiveview, top elevation and sectional view of the platform portion of theinvention to better illustrate a portion of the structure forming thenon-linear orifice;

FIG. 7 is a perspective view of the rocker and platform portions of theinvention as they are installed onto the lower portion of the devicehousing for producing an oscillatory positive expiratory air pressure;

FIG. 8 is a perspective view of the assembled device with the upperportion of the device open to better illustrate a portion of thestructure for adjusting the magnitude and frequency of the oscillatorypositive expiratory air pressure and the ease in which the device may beassembled and disassembled for cleaning;

FIG. 9 is a top elevation view of the assembled device;

FIG. 10 is a sectional view of the device as illustrated in FIG. 9 takenalong lines 10-10 to better illustrate the internal structure forcreating the oscillatory positive expiratory air pressure and to controlthe oscillatory frequency and pressure, and the manner in which themagnitude and frequency of the oscillations can be adjusted;

FIG. 11 is a rear perspective view of an adjustment dial portion of theinvention to better illustrate the manner in which the platform portionillustrated in FIGS. 3-6 is positionable relative to the rocker portionillustrated in FIG. 2 to determine the magnitude and frequency of theoscillations;

FIG. 12 is a planar view of the adjustment dial illustrated in FIG. 11to better illustrate the structure and function thereof;

FIG. 13 is a mechanical schematic of a second embodiment of theinvention utilizing dual rocker and platform assemblies to generate anoscillatory positive expiratory air pressure;

FIG. 14 is a mechanical schematic of a third embodiment of the inventionutilizing the platform and rocker assembly as illustrated herein, butwithout a magnet control to generate an oscillatory positive expiratoryair pressure; and

FIG. 15 is a mechanical schematic of a fourth embodiment of theinvention utilizing a spring-biased air-flow closure to generate anoscillatory positive expiratory air pressure.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, there is illustrated in FIGS. 1 and 2 anoscillatory positive expiratory pressure (PEP) respiratory therapydevice 1000 for applying oscillatory positive expiratory air pressure(PEP) therapy to a patient. When expiratory air is passed from a patientthrough an air-flow tube 200 to an expiratory-air-driven oscillatoryrocker assembly 400 contained within a two-part housing 300, theexpiratory-air-driven oscillatory rocker assembly 400 creates anoscillatory positive expiratory air pressure which is applied to thepatient during exhalation. The expiratory-air-driven oscillatory rockerassembly 400 comprises two portions, a rocker portion 440 and a rockersupport or platform portion 480 which act together in creating theoscillatory PEP therapy and are best illustrated in FIGS. 2-10. Thedetails of the structure and operation of this oscillatory PEP portionof the device will be described in detail hereinafter.

To control the magnitude and frequency of the oscillatory pressureapplied to a patient, a rotatable frequency control dial 350 is carriedby and positioned at the discharge end of an air-flow tube 200. Theair-flow tube 200 is carried by a lower housing portion 302, andsupports the rocker assembly 400. By operation of the adjustablefrequency control dial 350 in a manner to be hereinafter described, therelative positioning between the oscillatory PEP inducing portions ofthe oscillatory rocker assembly 400, the rocker portion 440 and therocker support portion 480, is adjusted to control the magnitude andfrequency of the oscillatory expiratory air pressure.

The expiratory-air-driven oscillatory rocker portion 440 is bestillustrated in the exploded view of FIG. 2, and FIGS. 7, 8 and 10. Therocker support portion 480, which functions in cooperation with therocker portion 440 to produce an oscillatory expiratory air flow andpressure, is also illustrated in the exploded view of FIG. 2, and inmore detail in FIGS. 3 through 6 and 10. The expiratory-air-drivenoscillatory rocker portion 440 and the rocker support portion 480, whenassembled together, form the rocker assembly 400.

The rocker assembly 400 is supported on the air-flow tube 200 whichcomprises a sealed chamber from a patient input end 201 to a dischargeopening 203 which is periodically closed to create the oscillatory PEPtreatment. In this manner, the rocker assembly 400 functions to createan oscillatory positive expiratory air pressure and flow rate inresponse to a patient's exhalation, and the patient's expiratory air isthereby directed to and through the rocker assembly 400.

As best shown in FIGS. 2, 7 and 10, there is illustrated the air-flowtube 200 having a first or patient input end 201 for receiving astandard 22 mm mouthpiece 202 into which a patient discharges expiratoryair. The air passed into the air-flow tube through the input 201 passesout of the air-flow tube 200 through a discharge opening 203, and isapplied to the rocker assembly 400. The air-flow tube discharge opening203 is formed in the top flat planar surface 205 of the air-flow tube200 and the expiratory air passed there through is applied to theoscillatory rocker assembly 400 for creating the oscillatory PEP therapyfor the patient in a manner to be hereinafter described in detail.

While a second opposite end of the air-flow tube could be closed, forconvenience of use, the opposite end 204 is open and carries aconventional one-way flapper valve 225. The flapper valve 225 allows apatient to draw inspiratory air into the air-flow tube 200 through theopening 204, but prevents expiratory air from being passed out of theair-flow tube 200 through the opening 204. To this end the one-wayflapper valve 225 is positioned on a spider 206 which is inserted intothe opening 204 against a shoulder forming a space sufficient for theone-way operation of the valve. Upon inhalation by a user, the valve 225opens and allows air to pass into the air-flow tube 200, and uponexhalation, the valve 225 is held closed against the spider 206 therebypreventing expiratory air from passing out through the valve 225. If theend 204 were closed, a user would not be able to inhale through thedevice 1000, but that would not effect the operation of the device inproviding oscillatory PEP therapy in the manner to be described herein.

After the expiratory air is applied to the rocker assembly 400, the airthereafter exits from the device 1000 through openings in the rotatableadjusting dial 350 carried in the housing 300.

As best illustrated in FIGS. 2, 7, 8 and 10, the rocker portion 440 isbalanced for pivotal movement about pivot pins 441 on spaced pivotsupports 481 formed on a platform 485 of the rocker support portion 480.The pivot pins 441 form a transverse pivot axis for the rocker portion440 which lies in a plane above and extends transverse to thelongitudinal axis of the platform 485. The pivot pins 441 are limited intheir axial and vertical movement by a pair of locking guides 482,carried by the platform 485, one of which is positioned adjacent each ofthe pivot supports 481 to maintain the pivot pins 441 in their properposition on the pivot supports 481. In this manner the rocker portion440 is pivotal relative to the rocker support portion 480 regardless ofthe orientation of the device 1000, allowing the oscillatory PEP device1000 to function regardless of its orientation in use. A balance pad 442and balancing cylinder 443 are formed at one end of a rocker arm 445 tobalance the weight of a cone-shaped air-flow closure member 447 and apin of magnetically attractable material, such as a steel pin 448, bothof which are carried at the opposite end of the rocker arm 445. The pin448 is carried at the distal end of the rocker arm 445 by a plurality ofgripping fingers 446 which partially encircle the pin 448 for holdingthe pin in a position to be exposed to the magnetic field of adisc-shaped magnet 488 carried on the air-flow tube 200 in a magnetholder 490.

The cone-shaped air-flow closure member or air-flow closure cone 447 issized and positioned on the rocker arm 445 to be periodically insertedinto a tapered bell-shaped or trumpet-shaped air-discharge outlet 487formed in the platform 485 to create the oscillatory PEP when expiratoryair is discharged through the opening 203 in the air-flow tube 200. Asbest illustrated in FIGS. 3-6, the interior of the air-discharge outlet487 has a non-linear taper or bell-shaped interior surface to form anon-linear air discharge outlet for creating the oscillatory PEP therapyin response to the pivotal movement of the air-flow closure cone 447 into and out therefrom. In this manner the discharge outlet 487 isperiodically closed and re-opened allowing the expiratory air dischargedthere through to be discharged from the housing 300 through the openingsin the adjusting dial 350.

The oscillatory rocker assembly 400 is secured on the air-flow tube 200and positioned within the housing 300 by means of a positioning tang 484which extends downwardly from the platform 485 as best illustrated inFIGS. 2, 4 and 6. A pair of side walls 486 of the platform 485, thebottoms of which rest on the planar surface of the air-flow tube 200,are formed with a ridged finger-engaging surface to facilitate theremoval and repositioning of the rocker support portion 480 relative tothe air-flow tube 200 for cleaning the device 1000 as necessary.Sidewalls 209 extend vertically outward from the planar surface 205 ofthe air-flow tube 200 and are spaced apart a distance sufficient toreceive the rocker arm 445 there between. In this manner, the rocker armis protected between the sidewalls 209 when the upper and lower housingportions, 301 and 302, respectively are separated for cleaning. Thispositioning protects the rocker assembly 400 from being inadvertentlyimproperly grasped by a user when disassembling the device 1000 forcleaning, and the user's attention is directed to the ribbed or ridgedfinger-engaging surface of the side walls 486 which are preferred forgrasping when the rocker assembly is to be removed.

The tang 484 is secured in a channel 284 extending upwardly from the topof the planar surface 205 of the air-flow tube 200 to securely positionthe oscillatory rocker assembly 400 onto the air-flow tube 200. In thismanner a circular guide 489 engages with a cowling 287 of thecomplementary air-flow tube discharge opening 203 so that the non-lineartapered, bell-shaped discharge outlet 487 carried by the platform 485 isaligned in fluid communication with and extends into the dischargeopening 203 in the air-flow tube 200. Another tang 384 extendsdownwardly from the interior of upper portion 301 of the housing 300 andpasses through an aperture 444 in the rocker arm 445 to press downwardlyagainst the platform 485 thereby securing the oscillatory rockerassembly 400 in the proper position on the air-flow tube 200 when theupper 301 and lower 302 portions of the housing 300 are engaged.

The upper and lower portions of the housing, 301 and 302, respectively,are pivotally connected to facilitate the opening and closing of thehousing such as when it is desired to clean the interior thereof. Tothis end, as best illustrated in FIGS. 2 and 8, the upper housing 301 isformed with a pair of tabs 303 for engaging a pair of complementarypivot pins 306 formed on the lower housing 302 in a position to engagethe tabs 303 to form a pivotal connection therewith. A plurality of pins307 extend outwardly from the upper housing 301 to engage complementaryreceptacles 308 formed on the lower housing 302 to maintain the twoportions of the housing closed unless it is desired that they be openedfor access to the interior of the housing 300. When it is desired toopen the housing 300, the sides of the upper housing portion 301 arecompressed towards each other to facilitate releasing the pins 307 fromthe receptacles 308. When the pins 307 are so positioned, the twohousing portions 301 and 302 are enabled to be pivoted relative to eachother about the pivot connection 303, 306 providing access to theinterior of the housing 300 and the components enclosed therein. Asecuring tab 305 extends outwardly from the end of the upper housing 301opposite to the tabs 303 to engage a complementary recess formed in thelower housing 302 to facilitate securing the two housing portions 301,302 of the housing 300 together and the mouthpiece 202 is passed overthe tab 305 when place onto the end 201 of the air-flow tube 200.

To create the periodically interrupted discharge of expiratory air forapplying the oscillatory PEP therapy to a patient, the magneticallyattractable material or steel pin 448 is carried on the pivotal rockerarm 445 at a position in operative proximity to the magnet 488 carriedby the rocker support portion 480. While the rocker assembly 400 may beconstructed without magnetically attractable material and amagnet/magnet holder, the device 1000 will still provide oscillatory PEPtherapy. The use of the magnetic material and magnet/magnet holderpermits the device 1000 to control the magnitude and frequency of theoscillations.

The magnet 488 is carried in a magnet holder 490 having a receiverportion or pocket 491 formed in a circular configuration for receivingthe disc-shaped magnet 488, and has a plurality of gripping or centeringfingers 492 for retaining the magnet 488 in the circular-shaped receiverpocket. The receiver pocket 491 is formed at one end of a verticallypositionable carrier 495, which is guided in its vertical movement by apair of guide rails 210 extending outwardly from the flat planar surface205 of the air-flow tube 200. The opposite end of the carrier 495extends vertically upward from a position adjacent to thecircular-shaped receiver pocket 491 and terminates in a follower tip 496which engages a cam surface 396 formed in the oscillation frequencycontrol dial 350, as illustrated in FIGS. 7, 8 and 11.

In this manner, rotation of the frequency control dial 350 will move thefollower tip 496 causing the carrier 495 to move vertically between theguide rails 210. Raising or lowering the carrier 495 moves the magnet488 towards or away from the steel pin 448 to vary the magneticattractive force there between. Rotation of the frequency control dial350 controls the frequency of the oscillations by which the PEPtreatment or therapy is applied in accordance with the desires of thehealthcare provider. While the device 1000 will function to provide anoscillatory PEP pulse without the use of the magnetic field between themagnet 488 and the steel pin 448, because of the opening and closing ofthe tapered non-linear discharge outlet 487 due to the movement of thetapered cone-shaped air-flow closure 447 induced in response to thepatient's discharge of expiratory air, the use of the magnetic fieldpermits the device 1000 to provide an adjustable range in the pressureof the patient's expiratory air discharge required to create theoscillatory positive expiratory pressure pulses.

To assist a patient or the healthcare provider in using the device 1000once the proper magnetic field has been set, a plurality of indicia 310are spaced along the control dial 350 and the top of the upper portion301 of the housing 300. These indicia 310, in combination with a basereference point 360 on the upper housing 301, are used to ensure thatthe correct setting is being maintained after the healthcare providerhas established the desired level for treatment. To minimize theoccurrence of the rotatable adjusting dial 350 being unknowinglyrotated, as best illustrated in FIG. 2 a series of tooth-likeprojections 211 are formed on the air-flow tube 200. These projectionsare engaged by a mating tooth 351 formed on a thin chord 352 of plasticmaterial from which the adjusting dial 350 is constructed, and whichextends across the lower internal portion of the adjusting dial to forma sounding board. In this manner, when the rotatable adjusting dial 350is turned, the tooth-like projections 211 and the mating tooth 351provide resistance to movement and produce a mechanically generatedaudible sound to signal that a change in position has occurred. A pairof stops 354 are formed on the interior of the adjusting dial 350, bestillustrated in FIGS. 11 and 12, which in combination with a side portion309 of the lower housing 302, limit the rotational movement of the dial350 relative to the housing 300.

The rotatable adjusting dial 350 is rotatably mounted on the end of theair-flow tube 200 adjacent to the end 204 thereof, and is held incontact by a snap fit therewith and guides 355 which provide three pointcontact between the dial 350 and the end of the air-flow tube. Asexpiratory air is passed through the rocker assembly 400 the air willfreely flow from the housing 300 through the spaces between the housing300 and the adjusting dial 350.

Referring now to the embodiments illustrated in FIGS. 13 and 14, thereare illustrated two additional embodiments of the invention utilizing arocker assembly 400 carried on an air-flow tube 200. In the embodimentillustrated in FIG. 13, two cone-shaped air-flow closure members orair-flow closure cones 447 are utilized supported, one at each end, on arocker arm 445 a pivotally mounted at the approximate center thereof formutually exclusively closing and opening one of a pair of complementarytapered bell-shaped or trumpet-shaped air-discharge outlets 487 formedin the air-flow tube 200 carried within a housing 300, not shown in thisillustration. As shown in this Fig. the end 204 of the air-flow tube isclosed, but could be formed with a one-way valve 225 as previouslydescribed. In this embodiment it is believed that the flow of air out ofone of the air-discharge outlets 487 will cause the complementaryair-flow closure cone 447 to be accelerated downwardly increasing thepressure in the air-flow tube such that the other air-flow closure cone447 will be forced upwardly from its associated air-discharge outlet 487until the flow of expiratory air through the outlet 487 and over thecombination of the conical surface of the air-flow closure cone 487 andthe tapered non-linear orifice of the air-discharge outlet 487 willcause the cone 447 to be accelerated downwardly towards the outlet 487repeating the cycle and generating an oscillatory expiratory air pulseto the user as the two discharge outlets are cycled on and off.

The embodiment illustrated in FIG. 14 is similar to the embodimentdescribed herein without the magnetic 488 and magnet carrier 495. Inthis embodiment there would be no oscillatory frequency control and,therefore, no need for a frequency adjusting dial 350. The unit wouldnot be operable in all orientations, but would still provide oscillatoryPEP therapy at a fixed frequency which would be dependent upon theweight of the rocker assembly components.

In the embodiment illustrated in FIG. 15, the air-flow tube 200 has anopen end 204 through which expiratory air passes after passing through amodified air-flow closure cone 447 and associated air-discharge outlet487. The air-flow closure cone 447 is mounted on a spring-loaded shaft447 b which is adjustable to vary the force which is applied to hold theair-flow closure cone 447 against the expiratory air pressure appliedthrough the associated air-discharge outlet 487. When the expiratory airpressure increases above the spring force applied to the air-flowclosure cone 447, the expiratory air will be discharged through theassociated air-discharge outlet functioning in the manner here to foredescribed and causing an oscillatory PEP to be applied to the user.

INDUSTRIAL APPLICABILITY

During use of the variable frequency or oscillatory PEP device 1000 apatient's expiratory air is delivered through the input end 201 of theair-flow tube 200 and passes through the opening 203 to the oscillatoryrocker assembly 400. Accordingly, the expiratory air pressure is appliedagainst the cone-shaped closure 447 of the rocker assembly 400 whichforms a closure of the non-linear discharge opening or orifice 487. Thepressure of the patient's expiratory air will raise the cone-shapedclosure 447, causing the rocker portion 440 to pivot about the pivotpins 441 against the force of the magnetic field between the magnet 488carried on the pivotal rocker support portion 480 and the steel pin 448carried on the rocker assembly 400. As the cone-shaped closure 447 movesupwardly in response to the increasing expiratory air pressure, theconstant taper of the conical shape in conjunction with the bell-shapednon-linear taper of the non-linear discharge opening or orifice 487increases the effective discharge area thereby decreasing the airpressure applied against the cone-shaped closure 447 and reducing theupward acceleration of the rocker arm 445.

When the magnetic force and the Coanda effect of the air flow over thebell-shaped or non-linear tapered interior of the discharge outlet 487overcome the expiratory air pressure applied to the tapered cone-shapedclosure 447, the closure 447 will again begin to move downwardly andaccelerate into the bell-shaped non-linear-tapered discharge orifice487. As the cone descends into the air flow path through the dischargeoutlet or orifice 487, the annular flow area diminishes reducing theairflow rate and increasing the air pressure. This continues until thedownward momentum is overcome and the cone 447 resumes its upwardacceleration. Maximum pressure is obtained at this point and anothercycle begins.

While this invention has been described in the specification andillustrated in the drawings with reference to preferred embodiments, thestructures of which have been disclosed herein, it will be understood bythose skilled in the art to which this invention pertains that variouschanges may be made and equivalents may be substituted for elements ofthe invention without departing from the scope of the claims. Therefore,it is intended that the invention not be limited to the particularembodiments disclosed in the specification and shown in the drawings asthe best modes presently known by the inventors for carrying out thisinvention nor confined to the details set forth, but that the inventionwill include all embodiments modifications and changes as may comewithin the scope of the following claims:

1. An oscillatory positive expiratory pressure therapy device,comprising: an air-flow tube having a path of air flow movement from aninlet opening for receiving expiratory air passed thereto by a userreceiving respiratory therapy or care, through an outlet opening fordischarging the expiratory air passed through said inlet opening; saidair-flow tube including expiratory air responsive closure meanspositioned in said path of air flow movement and actuable between anopen position and a closed position in response to the pressure ofexpiratory air passed thereto; said expiratory air responsive closuremeans including a normally closed non-linear discharge outlet which isopened in response to the presence of a predetermined pressure ofexpiratory air being passed in said path of air flow movement, and whichcloses in response to a predetermined rate of air pressure decreasethrough said non-linear discharge opening; and wherein said expiratoryair responsive closure means positioned in said path of air flowmovement and actuable between an open position and a closed position inresponse to the pressure of expiratory air passed thereto comprises anoscillatory rocker assembly including a rocker portion having acone-shaped air-flow closure member pivotally supported on a rockersupport portion to engage a tapered bell-shaped air-discharge outlet toform said non-linear air discharge outlet.
 2. The oscillatory positiveexpiratory pressure therapy device of claim 1 wherein said non-lineardischarge outlet positioned in said path of air flow movement comprisesa non-linear tapered discharge orifice.
 3. The oscillatory positiveexpiratory pressure therapy device of claim 1 wherein said non-lineardischarge outlet positioned in said path of air flow movement comprisesa bell-shaped discharge orifice.
 4. The oscillatory positive expiratorypressure therapy device of claim 1 wherein said non-linear dischargeoutlet positioned in said path of air flow movement comprises atrumpet-shaped air discharge outlet.
 5. The oscillatory positiveexpiratory pressure therapy device of claim 1 further including amagnetic force field applying means for generating a biasing forceeffecting the opening and closing of said non-linear discharge opening.6. An oscillatory positive expiratory pressure therapy device,comprising: an air-flow tube having a path of air flow movement from aninlet opening for receiving expiratory air passed thereto by a userreceiving respiratory therapy or care, through an outlet opening fordischarging the expiratory air passed through said inlet opening; saidair-flow tube including expiratory air responsive closure meanspositioned in said path of air flow movement and actuable between anopen position and a closed position in response to the pressure ofexpiratory air passed thereto; said expiratory air responsive closuremeans including a normally closed tapered trumpet-shaped air-flowdischarge outlet which is opened in response to the presence of apredetermined pressure of expiratory air being passed in said path ofair flow movement, and which closes in response to a predetermined rateof air pressure decrease through said discharge opening; and saidexpiratory air responsive closure means including a cone-shaped air-flowclosure member pivotally movable in response to expiratory air pressurebetween a closed position into engagement with said taperedtrumpet-shaped air-flow discharge outlet blocking the flow of expiratoryair in said path of air flow movement and an open position permittingthe flow of expiratory air in said path of air flow movement therebyforming a non-linear discharge outlet.